I need a potion to increase the percentage of smithing, healing and etc.
You increase your alchemy skill, either via enchanted gear, an alchemy potion, or both. I don’t know if it still works on newer releases, but it used to be a thing to cheese the crafting system by making an alchemy potion, drink it, make a better alchemy potion, rinse repeat. Then once it’s high enough you make powerful smithing and enchanting potions and then use those to craft gear (rings, gloves) to permanently enhance your crafting.
There is no Fortify Alchemy potion recipe in Skyrim. That was Morrowind cheese.
However, there is a bug in Skyrim that makes Fortify Restoration potions act like Fortify Alchemy potions.
Ah, you’re right! I got them mixed up.
Raising your skill in alchemy and the alchemy skill tree.